That's a click bait study if I ever saw one
There are widespread claims1 that YouTube radicalizes some users. Those claims are generally poorly supported. This study seeks to provide evidence, using a documented methodology,2 for or against that thesis.
That's valuable regardless of whether the thesis is correct. That's how research works: we find a question that's of interest to an audience, and we then we try to find evidence supporting one or another answer to that question.
Maybe you think the answer is obvious. Well, guess what, Sunshine: your opinion isn't worth any more than those of the other people making unsupported claims about the matter, and probably less than some. On the other hand, here we have some people who actually put some work into answering it. So perhaps you should have a little respect for what they've done.3
1OK, here's a citation.
2Whether the methodology is sound is a separate question.
3But you won't, will you? Because being a superior know-it-all ass is par for Reg commentators.